Within the general population, parents and teachers worry about children's tendencies to overcontrol their behavior or to demonstrate signs of undercontrol in early life, and a significant percentage of these children go on to develop psychopathologies. In order to understand what sets children on disparate pathways of risk or resilience for later psychopathology, it is important to identify early associations between physiology and behavior as the foundations underlying mental disease. The current proposal seeks to examine multiple indicators of the stress response system and how they coordinate in order to identify patterns of physiological risk that predict early individual differences in trajectories of behavior problems across early childhood and how caregiving may affect or change the association between physiology and behavior problems in an economically and racially diverse sample, goals that closely mirror the NIMH strategic aims. A consistent biomarker for risk has not been established in early childhood. Recently, studies indicate that a new biomarker of sympathetic nervous system (SNS) activity, salivary alpha-amylase (sAA), shows great promise as a predictor of early behavior problems. In addition, there is some evidence to suggest that physiological stress systems interact with each other rather than contribute independently to behavior problems, a model that may better represent the complexity of development. Thus, the current proposal examines the interaction of hypo-pituitary-adrenal (HPA) system and the SNS system in order to identify patterns of physiological risk for behavior problems. Whether those behavior problems are manifested is most likely influenced by the environment. One of the most salient contexts for a toddler is the caregiving environment, and caregiver behaviors such as sensitivity and intrusiveness are associated with individual differences in behavior problems. The Durham Child Health and Development (DCHD) study is an ideal dataset for this proposed project. This study has demographic, behavioral, self-report, parenting and physiological data for 206 families recruited to be relatively equal in the number of white and black families and lower- and higher-income groups. At 24 months of age, parenting behaviors, such as sensitivity and intrusiveness, were coded during parent-child challenge tasks. The Child Behavior Checklist (CBCL) was completed by the mother at 18, 24, 30, 36 months of age. Salivary cortisol, a well researched marker of HPA arousal, was collected and assayed at 18, 24, 30 and 36 months of age. The current study proposes to re-assay existing saliva samples to obtain an additional physiological measure, sAA. It is yet unclear the role sAA plays in predicting behavior problems, whether stress systems contribute independently or interactively to risk for behavior problems, whether a certain pattern can be identified, and whether caregiving behaviors may affect this association. The current proposal has the potential to add greatly to our knowledge by examining early foundations of mental disease over time and to address these issues from a person-oriented and multi-level perspective. PUBLIC HEALTH RELEVANCE: The Federal Agency Forum on Child and Family statistics reports that in 2007 approximately 5% children aged 4-17 were rated by their parents as having serious emotional or behavioral difficulties, including problems managing their emotions, focusing on tasks, and/or controlling their behavior;this number jumps to 7% when families live below the poverty line. The proposed study is designed to examine early behavior problems at multiple levels of analysis, including biological and environmental variables in a racially and economically diverse sample. In line with the NIMH strategic goals, this proposal may help to identify biomarkers of risk for problematic behavior while also examining salient contextual variables. Establishing biomarkers of early risk may help us understand the foundations for later mental disease and also help to target interventions at a time in development when these maladaptive patterns have not yet fully organized.